Previous multiple axle suspensions, for example those disclosed in U.S. Pat. No. 3,632,128, have means for mounting the axles for substantially independent movement to a vehicle chassis. These devices allow movement of the axles, and attached wheels, etc., in a vertical direction to allow the vehicle to track on all wheels as it transverses bumps or obstructions, and are adequate to do so.
Known suspensions have means to compensate for loading of each axle to distribute dynamic and static loads more evenly between the axles of the assembly, however, the suspension of this invention utilizes a load equalizing beam resiliently mounted to the vehicle chassis and mounted to move with the vehicle axles to provide unique and improved load distribution.
This invention relates to a multiple axle vehicle suspension assembly and particularly such an asembly wherein a resilient means may be utilized for resiliently supporting the load on the vehicle axles by means of a load equalizer beam that connects the axles to distribute the load therebetween.
The suspension assembly of this invention generally comprises a hanger mounted to and depending from the vehicle chassis, a first torque arm pivotally mounted by means of a resilient bushing at its rearward end to the hanger assembly with a forward vehicle axle mounted to its forward end. A second torque arm is pivotally mounted at its forward end by means of a resilient bushing to the hanger with a rear axle mounted to its rearward end. Thus, the first torque arm extends forwardly from the hanger with the forward axle mounted thereto, and the second torque arm extends rearwardly from the hanger with the rear axle mounted thereto.
A beam extends between the vehicle axles with the forward end of the beam opposing loading of the forward axle and the rearward end of the beam opposing loading of the rear axle. A resilient means, such as an elastomeric ball, is mounted between the beam and the vehicle chassis and attaches the beam to the vehicle chassis. As load is applied to one of the vehicle axles, it is transferred in part to the other axle and to the vehicle chassis through the elastomeric ball. Operation of the beam acts to equalize the load between the rear and forward axles.
In one preferred embodiment of the invention the forward and rear ends of the beam bear downwardly directly on the forward and rear axles of the vehicle. In another preferred embodiment of the invention, resilient means, such as elastomeric balls, are mounted between the axles or the pivot arms and the ends of the beam, to act along with the resilient means between the beam and the vehicle chassis in carrying the vehicle load.
Thus, it is a primary object of this invention to provide a multiple axle vehicle suspension which utilizes a load equalizer beam that spans the axles of the vehicle. The suspension has resilient means between the load equalizer beam and vehicle chassis to support at least a portion of the vehicle load and allow resilient rocking or pivoting of the vehcle load equalizer beam. The pivoting movement operates to distribute the load between the axles under conditions where one axle is loaded more heavily than the other.